1. Field of Invention
The present invention relates to a fluid heating device and wherein the fluid is heated by electromagnetic induction, and more specifically wherein a fluid passes through a secondary electrically conductive jacket which surrounds the primary or vice versa and wherein the temperature of the fluid is controllable to maintain a substantially constant output fluid temperature as well as maintaining the conductive jacket at a substantially constant temperature.
2. Description of Prior Art
There is known an apparatus to produce heat by using a thermo-inductive generator and wherein a plurality of tubular windings are disposed about the secondary whereby to regulate the temperature of the fluid. Each of the individual tubular windings is short-circuited. A thyristor valve is also associated with individual windings whereby one or more windings in the flow path of the liquid may be activated thereby controlling the temperature thereof within certain tolerances which are not very accurate. Accordingly, by appropriate control of the thyristors, certain portions of the secondary winding can be cut off. Such a three-phase system is briefly described in an article published by Compagnie Generale de Chauffe in 1985. A disadvantage of the above-described thermo-inductive heat generator is that it is bulky, consumes a large quantity of energy, is used only for large industrial applications such as the production of steam. It is also pointed out that such heat generating transformers have many advantages in that they require very little servicing, do not pollute, may be controlled automatically, and could quickly produce heat. They are also simple to install and have a high thermal efficiency. They also have an excellent power factor at full power in having a multitude of applications.